1. Field of the Invention
The invention lies in the field of conveyor technology and processing technology of flat products, in particular of printed products such as newspapers, periodicals and magazines. It relates to a method and to a device for creating a flow of flat products in a defined sequence or succession, in particular with the purpose of further-processing in this defined sequence. A preferred application is in mailroom technology, on putting together, and, as the case may be, addressing different products in a defined sequence in accordance with a predefined sequence of addresses, which for example corresponds to a mailing route.
2. Description of Related Art
In mailroom technology, different products must be put together in a manner which is assigned to the addressees, and addressed, as the case may be, and grouped into groups (e.g. as small stacks). The background of this is the fact that as a rule, different products must be dispatched in a set number to certain addresses, wherein the addressees must be sought in a certain succession (mailing route). Hereby, there is the demand that at least one, or generally each product, which is envisaged for a certain addressee, is individualised with the address concerned.
For this reason, there exists the need to set up the complete product flow already in the defined sequence, before the products are processed further. A further-processing may include the addressing of all or selected products and/or the formation of groups/stacks, as the case may be, before or after packaging individual products or product groups. A sequence of products of the type A, B, C, . . . for example may be as follows: AAABBCCCCCAAABBBC . . . , wherein the first three exemplars of product A, the first two exemplars of product B and the first five exemplars of product C for example are envisaged for a first addressee, the next four exemplars A, three exemplars B and one exemplar C are envisaged for a second addressee, etc. The sequence may also look as follows: (ABC)(ABC)(AB)(AC)(BC), wherein in each case products collated on top of one another are indicated by brackets. Such products are assigned to one end product or addressee, for example the products may be individualised supplements, which are inserted into a newspaper in a further processing step. A printer arranged after the sequence creation may then, for example, print the addresses correct to sequence, and the products may be subsequently grouped into groups and/or stacks correct to sequence and be delivered according to a defined mailing route (sequence of receivers).
The products may be present in the product flow in an individual manner or completely or partly overlapping. It is often necessary for at least a part of the product surface to be accessible for a subsequent addressing of all products.
An incorrect or missing product leads to the fact that the product sequence is shifted and thus the subsequent steps, in particular the addressing according to an address list, no longer match. Even without a subsequent addressing, an error may lead to the fact that a product succession is present, which is no longer correct with regard to sequence, in particular with regard to the mailing route. As a whole, one desires to avoid, as much as possible, a propagation of the error caused by an incorrect product sequence, in the subsequent processing steps.
EP-A 0 511 159 describes a method as well as a corresponding device which serves for composing more complex products by way of inserting part-products into a main product. Thereby, different products supplied as continuous flows are led together into groups on at least one grouping path, realised by way of conveyor belts. Each group is to have a defined sequence of products. In order to avoid errors in the deposited product flow on account of errors in the supply, it is suggested to buffer the products already in supply flow, before release to the grouping path, e.g. by way of suitable intermediate conveyors. The release is to be effected only when an adequate number of products for creating a complete group are present in all buffers. As the case may be, the creation of a group is delayed until this is the case. Thereby, one accepts the fact that the deposited product flow has gaps. This however is not a problem, since here it is not the case of a composition of an infinitely long product flow, which is correct with regard to the mailing route, and moreover, also does not address.
A similar method is known from EP-A 1 475 329. Here, several products are prepared simultaneously and deposited as a finished part-imbricate formation, instead of individually depositing the products. Likewise, only sections (short product sequences) are processed, without addressing the products.
The known methods are above all envisaged for composing printed products out of several part products, for example for manufacturing pamphlets or books from several kerfs, or for inserting different supplements into folded newspapers. Hereby, it is always the case of groups with a relatively small product number, for which the necessary intermediate storage means may be realised without great effort. However, larger intermediate storage means are required for creating longer sequences, in order, as the case may be, to be able to buffer all products which are to be released one after the other, until this release. The known method is therefore not suitable for creating infinitely long sequences, in particular with a large number of equal products in a part sequence (group), without any design adaptation of the applied device.
Moreover, according to the state of the art, one may only avoided errors on release of the products to the grouping path. An error in the created product flow may not be corrected and thus may likewise lead to sequence errors with the further-processing.